Rolling strip metal



Jah. 8, 1946.

4.1. w. Koss ROILING- STRIP METAL Filed Dec. 2o',v 1941 2 Sheets-Sheet 1 Joseph Wlfoss Jan. 8, 1946.v

.1.l w. Koss ROLLING STRIP METAL Filed Dec. 20, 1941 2 Sheets-Sheet 2 memes Jas. s, 194s UNITED STATI-:sg PATENT ori-'ica aonmsss' Mural .Y i Appiioaurenetoa iairito. szass (o1. izo- 32).`

12 Claims.

This invention relates to the art of rolling metal and is for a method and apparatus for cold rolling so-called continuous strip or sheet metal.

- In the rolling of lstrip or sheet metal, particularly ferrous metal, the final rolling operation is4 performed for the purpose of imparting certain physical characteristics to the metal. Thisis usually referred to as .temper rolling or sometimes as skin rolling. The object is to pass lthe metal betweenI work rolls, the eiIect of which is to elongate the metal only slightly and to affect its thickness very slightly. 'I'his cold working however, does develop the desired temper in the metal to suit it for the purpose for which it is to be v used.

'I'he amount of work which has to be done may passing through the min, although the mul itself operates continuously in one direction.

The invention saves considerable time over the usual method employing a single stand millbecause all of the'temper passes take place simultaneously and the strip material does not have to be passed ilrst through the mill and wound into a coil, then transferred to the opposite side of the mill and repassed one o'r more times through the mill, and it also saves time as'compared with a reversing mill. In this respect, the

invention provides all.the advantages of a multiple standmill. However, the present invention requires no vmore floor space than the usual single stand mill because only a single roll stand is necessary,l and in additionto the saving of iloor vary considerably depending upon the nature of the metal and the quality of the product'to be more passes are required tol properly flatten and temper strip steel which has been rolled and then annealed to dead softness to enable it to be used for ordinary purposes, such as the making of tin can stock or for similar purposes.

The most common practice is to run thestrip material two or more times through a single stand' mill, the material from the take up reel being transferred after one pass through the. mill laround to the unwindin'g station and repassed through the same mill. In some instances a single high reversing mill may be used. Another commonpractice is to have two or more stands of made. Most frequently two and often three or space it is much cheaper to construct and substantially cheaper to operate than a multiple stand mill which provides the same number of passes. Not only` does the invention provide the advantages ofv both single stand and multiple stand mills, but a further'advantage results over both of these types of mills due to the cold workrolls arranged in succession so that' the continuous listrip material. is pro roll passes of the several s nds of rolls in a single rolling operation'. If three temper passes are required, the mill is provided with three stands of rolls arrangedin succession.

According to the present invention temper rolling is accomplished by the use of a single stand mill having a multiple of work rolls so arranged as to provide a plurality of roll passes one above the other in the single -multiple high stand. The

' ively. engagedin theetel'lsthemnslahdlblltm ing which is imparted to the metal upon` being turned upon itself to travel first in one direction and then in the other.

The'ingention may be more fully understood by reference to the accompanying drawings which more or less schematically illustrate the invention and from which the method will appear. In the 1 drawings:

Figure 1 is a side elevation of a mill embodying my invention, various unessentiai parts of the mill being omitted and the housing, for the purpose of clearly showing the invention being illustrated in .dot-and-dash lines;

VFigure 2 is a view similar to Figure 1 but on a smaller scale,v showing an arrangement which may be employed on the mill of Figure v1;

Figure 43 isa view similar to Figure 2, showing -a 3high mill with only one driven roll; Figure 4 is a view similar to Figure 3, showing a 's-mgn mill with no rolls driven.

liigure5isadetailedpianviewshowingone formotlooper or tensioning means 'which may be i roll 2 is a backup roll 3 and below the work roll 5 is a backup roll 1. The roll housing, designated generally as 3, may be of any conventional form used in multiple high mills of this character.

At one side of the roll stand is a feeding station having a feed reel 9. Atthe other side of the mill is a takeup station having a winding or takeup reel I0. The feed and takeup reels 9 and III respectively, are of any usual or preferred con' struction, thefeed reel if necessary being provided with a brake as is the usual practice to maintain a tension on the strip being delivered to the mill whilev the takeup reel, I mayd also be driven at such a rate with respect tothe work rolls 3 and 4 as to maintain a tension on the strip. The strip material, designated generally as A, is fed from the feed reel 9 into the. pass between the .rolls 4 and 5. It is then looped by means of a looper or tension'means, designated generally as II and passes back through the mill between the rolls 3 and 4; It passes around a second looper II and is engaged in the pass betweenv the rolls 2 and .3. From here it is delivered to the takeup reel. A cluster of tensioning rolls I 3 of conventional form may be located between the last pass of the mill and the take-up reel I0.

A preferred form oflooper or tensioning means comprises a reciprocable frame orvsupport I4 in the end of which is mounted a roller I5. Carried on the frame I4 back of the roller I5 isa curved metalplate I 6. The support I4 is carried at theend of. a piston rod I1 and at I8 is a uid pressure cylinder. by means of which the support I4 may be moved toward and away from the work roll with which the looper cooperates.'

In the operation of the mill the rolls I5 of the looping device arel initially positioned close to the tending to move the rollers I5 away from the work rolls with which they cooperate, Thispressure is adjusted to the tension which it is desired to maintain on the material. Since the material elongates very slightly vin passing between the on the left-hand side of the as viewed in Figure 1 restrains-the trailing end of the material afterthe material'clears the pass between the work rolls 3 and 4.

In the operation 'of the mill the screw-down devices at the top of the mill are adjusted to maintain proper pressure `in the roll passes. ,As previously indicated, this pressure is suiilcient to work the metal in the strip with very little reduction in gauge and consequently very little elon- 'gation It is suflicient, however that with a number of passes the desired temper or other qualities V imparted by lcold working are acquired by the rolls 4 and 5, tending to form a loop in the strip y material, the roll I5 will be drawn back away from the work roll as the loop develops, keeping the strip material taut and under 'the necessary tens on.

' In addition to the tensioning devices, holddown devices may be used to keep the material tight when the trailing end of'the strip is passing through the mill. Two of these hold-down devices are shown. Each of them is designated 20. Each hold-down device'is shown as having a roller 2| adapted to ride on the strip material. This roller is supported at each end in the armsof a yoke 22 that is pressed down by a piston 23 in a fluid pressure cylinder '24, the yoke straddling"y the strip material.. When the trailing end of the ing the loop will be pressed against the surface of the roll .4 ancLwill travel between the roll 2l and strip. Because of the presence of the tensioning devices at each sideof the mill, the elongation which-does occur is taken 'care of and the material is nevertheless kept under the desired degree of tension. Not only does the mill temper the strip but it ilattens it as is required of mills of this character. In addition to the Working which is accomplished in the rollpasses the cold bending of the material around the looping rollsI5 gives additional working of the metal so that the degree oiv cold working accomplished in three passes ofv the material through this mill may actually be greater than that which would -be acquired in passing the material through a succession of single roll.passes. Since the work rolls 3 and 4 are both driven they must be of uniform diameter in order to rotate at the same speed.

Sometimes in the cold working of metal for temper rolling it is desirable that the surface of the material be roughened in one or more of the roll passes so as to increase the degree of cold Wo`rk`A ing imparted to the individual areas of the metal. This may be provided for in the present millb'y roughening in the conventional manner the surface of the work rolls 4 and 5. A smooth pass would then be provided between the work rolls 2 and 3. If only one surface of the metal is to be rough then one roll as for example 4 or 5 may have a rough surface. Moreover, by proper ar,- rangement of the roll surfaces, various nishes on the material can be secured. For example, by having two smooth facedwork rolls and two dull or rough work rolls, a bright smooth nlsh may be secured in a single pass through the two smooth rolls; or a dull nish may be secured by a single pass between the two dull rolls; or a semirough or dull iinish roll, one can selectively have.

one side bright and one dull. or one side bright and one semi-dull or both sides bright and smooth. The various commercial finishes heretofore obtainable only in multiple stand mills or in single stand mills with intervening roll changes may be selectively produced in this single stand mill with out in most cases, any roll change.

It will of course be understood that the direction in which the material 'travels back and forth through the mill is not important. Instead of the metal entering the lowermost pass between thel rolls 4 and l, the direction may obviously bethe uppermost pass changed so that it first enters between the rolls 2 and 3. Y v

Under some circumstances it may be desirable to so construct the multiple high mill thatthe metal can be given one, two or three passes, ac-` cording to the requirements 'of the ParticularA metal being rolled. When is to be donethe arrangement illustrated in Figure 2 may be employed. In Figure 2 the mill is essentially the'. saine, as thatshown in Figure.; and similar ref L the roll 4. In likemanner the hold-down device 'l5 erence numerals have been' However, in

-yand maintenance.v

' asoasas addition to several work rolls described, a series of small guide rolls designated generally as 2l may be mounted in the lower part of the roll housing. In this case the material may pass from the feed reel 9 to the takeup reel I0 in any.one of several ways. It may be passed through the mill once, going between the work rolls 3 and 4 for a sin le pass. It may be guided around the rollers 25 and then .passed between the rollers 4 and I and repassed through the rollers I and 4. With three passes the mill would be operated as shown in Figure 1. In the arrangement shown in Figure 2 the various hold-down and looping devices have not been shown,.except that onemills for carrying out the method, it will be understood that this is merely by way of illustration and that various changes and modiiications may j be made within the contemplation of my invention and under the scope of the following claims.

l. In the temper-rolling of strip metal, the steps which comprise simultaneously passing' the strip metal between a plurality of passes inja single multiple high mill, turning the strip over between the successive roll passes, and exerting tension to pull the loop of material between succes- 4ures 1 and 2, merely to illustrate that theinvention is not confined to a multiple high mill having both working and backuprolls, but the invention may be practiced and embodied in any multiple high mili having suitable workrolls arranged to provide more than a single pass.

In Figure 3 the' material, designated from the feed reel I4 around the lower work roll 33, passes between the work rolls 3i and 33, then passes around a looping or tensioning device 36 and repasses between thework rolls 3| and 32 and from there goes to the takeup reel 31. The looping device is similar to the device i I previously described. Holddown devices similar to the holddowndevice 2li of Figure 1 may be used, one to cooperate with the roll I3 and-'oneto cooperate with the roll shown. l

al, although these havenot been AIn the arrangement shown in Figure 4 none o'f the rol1s` is driven and the material is pulled through the mill under tension. This view'i1lus` trates a-multiplevhigh millsimilar to that shown in Figure 1. with four work rolls 40, 4i,'42 and 43.

I Backup rolls 'are shown at 44 and 45. The feed. reel is designated 46 and the takeup reel is designated 41. In this case all of the power required for rolling is applied to the takeup reel 41. "The feed reel 4 6 may be provided with a brake as iscustomary in the art. 'I'he material A" is illustrated as passing flrstfbetweenthe rolls 42 and 43 and then between rolls 40 and 4I. Looping and hold-down devices, designated 48 and 49 respectively, may be similar to those previously described.

A' is 'fed The method accomplished bythe apparatus4 shown in Figure 4, like the method in Figure 1, causes the material to be kept under tension between the successive roll passes. Additional cold workingis provided by .the fact that the material is folded back and forth as it passes, ,repasses and emerges .from the mill.

As hereinabove indicated, the mill of the present invention requires .no more iioor space than va conventional single stand or reversing mill and is only veryslightly more expensive tooonstruct.' At the same time each single roll stand gives the time saving advantage and choice of sive roll passes'away from the mill to compensate for elongation and maintain tension on the material between the successive roll passes.

2. In the temper rolling of strip metal, the steps which comprise simultaneously'passing the strip between a plurality of rolling passes in the same roll stand, bending the strip from its point of.

a pass between two of the work rolls to anotherl pass between two work rolls, whereby the material receives at least two passes in the same roll stand, and means apart from the mill cooperating with the strip for maintaining tension on the material in all of the passes.\

4. A multiple high mill having at least three work rolls providing aplurality of roll passes in a single roll stand, whereby strip material may be looped to travel first-through one pass and then through another, tensioning means about which the material travels from one pass to the next for maintaining tension on the material, and means in addition to the tensioning means for holding down the trailing ends of the strips between the successive passes.

5. A multiple high rolling mill having at least three work rolls superimposed in cooperating relation, means for guiding strip material. from a pass between two work rolls to another pass be tween two work rolls vwhereby the material simultaneously receives at least two passes inthe same roll stand, means other than the rolls for main- `tainingthe loop of material where it vemerges ing strip material to an s-shaped travel through the mill, whereby the same strip simultaneously moves through the three passes provided by the four work rolls, and tensioning means in each loop of the S-shaped' travel for taking up slack l resulting from the elongation of the strip;

' 'l. In the temper rolling of strip metal, the steps which comprise passing the strip from a' feeding station through aplurality of passes in a single multiple high mill to a takeup station and in the travel of the strip between successive passes, ap-

` plying tension to the strip and turning itV over` surface ilnislies of va multiple stand mill at a tremendously less cost for door space. equipment.

whue .r'have illustrated and described certain under tension. v 8. A multiple high mill then through another. means for feeding lstrip specific embodiments of my inventionandspecinc 1l material. tol the mill. for taking up strip having at least three work rolls providing a pluralityof roll passes in a'single roll stand, whereby strip material may Ibe looped to travel first through one pass. and

material from the mill, and means efl'ective upon the strip material in its passage between said passes for applying tension upon the material.

9. A multiple high rolling mill having at least three work rolls forming at least two successive passes for the rolling'of strip material, with the material looped outward from the rolls in the ini terval between the successive passes, means engaging the loop for guiding the strip between the passes, and means, cooperating with said last means for maintaining controlled tension on the materialin the loop whileit is being rolled, and supply "and take-up stations for the strip material being rolled.

10. In the temper rolling oi' strip metal, the steps which comprise passing the strip from a feeding station through a plurality of passes in the same roll stand. to a takeup station, establishing outward from the passes a loop in the strip advancing between two of said passes, eiecting in said loop compensation for elongation of the advancing strip and maintaining controlled tension thereon.

1l. 'I'he method of operating a multiple highy mill having at least three work rolls forming at least two successive passes to .eiect the temper rolling of strip material, which comprises passing the strip material from a feeding station through said passes'oi' the mill to a ltakeup station and in the ltravel of the strip material between said passes forming outward from the passes a loop in the strip material and\controllably applying' tension thereon.

- 12. The method of operating a multiple high mill having at least three work rollsforming at least two roll passes to eiect the temper rolling of strip material, which comprises passing the strip material from a supply station successively through said passes to a takeup station, and in the travel between said passes forming a loop in the strip material outward from the rolls and maintaining a controllable tension on the material constituting the loop and additionally applying tension in the material between the mill and the take-up station.

JOSEPH W. KOSS. 

